I can't give you any specifics on the Kona but I've had a Mutoh Ultima for 7 years and it was the predecessor to this plotter. They both share the same contour cutting system which is absolutely amazing. Cutting regular vinyl is good too. The only thing that disappointed me was that it needed to ship back to Arizona if service was needed. The Kona's may have better dealer service available.
I would buy a Kona in a heartbeat if I need a new plotter just based on my experience with the Ultima.
Hope that helps.